class_docstr: Checks the correct quoting of strings and binary objects.
  
  Since ver. 8.1, PostgreSQL is moving towards SQL standard conforming
  strings, where the backslash (\) is treated as literal character,
  not as escape. To treat the backslash as a C-style escapes, PG supports
  the E'' quotes.
  
  This test case checks that the E'' quotes are used whenever they are
  needed. The tests are expected to pass with all PostgreSQL server versions
  (currently tested with 7.4 <= PG <= 8.3beta) and with any
  'standard_conforming_strings' server parameter value.
  The tests also check that no warning is raised ('escape_string_warning'
  should be on).
  
  https://www.postgresql.org/docs/current/static/sql-syntax-lexical.html#SQL-SYNTAX-STRINGS
  https://www.postgresql.org/docs/current/static/runtime-config-compatible.html
code: def test_koi8(self):
      self.conn.set_client_encoding("KOI8")
      curs = self.conn.cursor()
      data = bytes(list(range(32, 127)) + list(range(128, 256))).decode(
          "koi8_r"
      )
  
      # as string
      curs.execute("SELECT %s::text;", (data,))
      res = curs.fetchone()[0]
      self.assertEqual(res, data)
      self.assert_(not self.conn.notices)
  
imports: from .None import testutils
  import unittest
  from .testutils import ConnectingTestCase, skip_if_crdb
  import psycopg2
  import psycopg2.extensions
  from psycopg2.extensions import adapt, quote_ident
label_desc: Use image node_id 6 for calling the QuotingTestCase obj's underlying member method code with example usage: obj.test_koi8() without return types